Skip to Main content Skip to Navigation
Conference papers

Optimizing Elliptic Curve Scalar Multiplication for Small Scalars

Pascal Giorgi 1, * Laurent Imbert 2, 1 Thomas Izard 1 
* Corresponding author
1 ARITH - Arithmétique informatique
LIRMM - Laboratoire d'Informatique de Robotique et de Microélectronique de Montpellier
Abstract : On an elliptic curve, the multiplication of a point P by a scalar k is defined by a series of operations over the field of definition of the curve E, usually a finite field Fq. The computational cost of [k]P = P + P + * * * + P (k times) is therefore expressed as the number of field operations (additions, multiplications, inversions). Scalar multiplication is usually computed using variants of the binary algorithm (double-and-add, NAF, wNAF, etc). If s is a small integer, optimized formula for [s]P can be used within a s-ary algorithm or with double-base methods with bases 2 and s. Optimized formulas exists for very small scalars (s 5). However, the exponential growth of the number of field operations makes it a very difficult task when s > 5. We present a generic method to automate transformations of formulas for elliptic curves over prime fields in various systems of coordinates. Our method uses a directed acyclic graph structure to find possible common subexpressions appearing in the formula and several arithmetic transformations. It produces efficient formulas to compute [s]P for a large set of small scalars s. In particular, we present a faster formula for [5]P in Jacobian coordinates. Moreover, our program can produce code for various mathematical software (Magma) and libraries (PACE).
Complete list of metadata

Cited literature [9 references]  Display  Hide  Download
Contributor : Pascal Giorgi Connect in order to contact the contributor
Submitted on : Wednesday, October 14, 2009 - 5:33:52 PM
Last modification on : Friday, August 5, 2022 - 10:45:46 AM
Long-term archiving on: : Tuesday, October 16, 2012 - 12:15:16 PM


Files produced by the author(s)



Pascal Giorgi, Laurent Imbert, Thomas Izard. Optimizing Elliptic Curve Scalar Multiplication for Small Scalars. Mathematics for Signal and Information Processing, 2009, San Diego, CA, United States. pp.74440N, ⟨10.1117/12.827689⟩. ⟨lirmm-00424282⟩



Record views


Files downloads